ORGN 127 |
| In our search for a new photoremovable protecting (caging) group we have investigated the photochemistry associated with three different chromophors. 9-Alkoxy-9,10-dihydroacridine, 4,4'-dimethoxytrityl ethers and 3-hydroxy-2-naphthalenemethanol ethers and esters were tested in order to examine their ability to release the protected compounds upon irradiation. 3-Hydroxy-2-naphthalenemethanol derivatives were found to be the most suitable for this purpose. Alkoxy and carboxy derivatives of 3-hydroxy-2-naphthalenemethanol release model substrates, i. e., benzoic acid and benzyl alcohol quantitatively with good quantum yields. The photodeprotection reaction is assumed to proceed via concerted exited state proton transfer, thus avoiding C-O bond heterolysis and the formation of ion pair. The commonly known problem of lowered photoefficiency of deprotection due to ion pair recombination is, therefore, circumvented.
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Asymmetric Reactions and Syntheses, Physical Organic Chemistry, Combinatorial Chemistry, Total Synthesis
8:00 PM-10:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Division of Organic Chemistry |